检索结果-南通市图书馆

INVARIANT DENSITY, LYAPUNOV EXPONENT, AND ALMOST SURE STABILITY OF MARKOVIAN-REGIME-SWITCHING LINEAR SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2011年第1期24卷 79-92页

作者： Qi HE gang George yin Department of Mathematics Wayne State University Detroit MI 48202 USA

This paper is concerned with stability of a class of randomly switched systems of ordinary differential equations. The system under consideration can be viewed as a two-component process （X（t）, α（t））, where the system is linear in X（t） and α（t） is a continuous-time Markov chain with a finite state space. Conditions for almost surely exponential stability and instability are obtained. The conditions are based on the Lyapunov exponent, which in turn, depends on the associate invaxiant density. Concentrating on the case that the continuous component is two dimensional, using transformation techniques, differential equations satisfied by the invariant density associated with the Lyapunov exponent are derived. Conditions for existence and uniqueness of solutions are derived. Then numerical solutions are developed to solve the associated differential equations.

关键词： Invariant density Lyapunov exponent randomly switching ordinary differential equation.

A New Flavanone and a New Flavanone Glycoside from Scutellaria baicalensis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第11期17卷 1457-1459页

作者： Jun gang yin Department of Applied Chemistry Yantai University Yantai 264005

A new flavanone （2S）-5, 7, 2＇, 5＇-tetrahydroxy-flavanone 1 together with a new flavanone glycoside （2S）-5, 7, 2＇, 5＇-tetrahydroxy-flavanone 7-O-13-D-glucopyranoside 2, were isolated from the dry roots of Scute... 详细信息

关键词： Scutellaria baicalensis Labiatae flavanone flavanone glycoside.

External Pressure Forming and Buckling Analysis of Tubular Parts with Ribs

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2006年第5期22卷 708-712页

作者： gang LIU Xuelian yin Shijian YUAN School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

Buckling and forming processes of tubes with varying slenderness ratio （ratio of length to diameter） under external hydraulic pressure were analyzed with three-dimensional finite element method （FEM） for studying tube external pressure forming （EPF）. Buckling pressures for different tube blanks without mandrel were predicted, and an EPF of a carbon steel tube onto a mandrel with six ribs was simulated. Both thickness distribution and buckling pressure from the simulations were found to be in agreement with those from experiments. Buckling pressures are shown to be a function of the slenderness ratio. The tubular part with six ribs produced by EPF has a uniform thickness distribution, whose maximum thinning rate is only 5.9%.

关键词： External pressure forming Hydroforming Lightweight component Buckling

Jump-diffusions with state-dependent switching:existence and uniqueness,Feller property,linearization,and uniform ergodicity

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2011年第12期54卷 2651-2667页

作者： XI FuBao yin gang Department of Mathematics Beijing Institute of Technology Beijing 100081 China Department of Mathematics Wayne State University Detroit MI48202 USA

This work focuses on a class of jump-diffusions with state-dependent switching. First, compared with the existing results in the literature, in our model, the characteristic measure is allowed to be a-finite. The existence and uniqueness of the underlying process are obtained by representing the switching component as a stochastic integral with respect to a Poisson random measure and by using a successive approximation method. Then, the Feller property is proved by means of introducing auxiliary processes and by making use of Radon-Nikodym derivatives. Furthermore, the irreducibility and all compact sets being petite are demonstrated. Based on these results, the uniform ergodicity is established under a general Lyapunov condition. Finally, easily verifiable conditions for uniform ergodicity are established when the jump-diffusions are linearizable with respect to the variable x （the state variable corresponding to the jump-diffusion component） in a neighborhood of the infinity, and some examples are presented to illustrate the results.

关键词： jump-diffusion sigma-finite characteristic measure state-dependent switching Feller property uniform ergodicity linearization

Improving students’programming quality with the continuous inspection process:a social coding perspective

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2020年第5期14卷 43-60页

作者： Yao Lu Xinjun Mao Tao Wang gang yin Zude Li College of Computer National University of Defense TechnologyChangsha410073China Key Laboratory of Software Engineering for Complex Systems Changsha410073China School of Information Science and Engineering Central South UniversityChangsha410012China

College students majoring in computer science and software engineering need to master skills for high-quality ***,rich research has shown that both the teaching and learning of high-quality programming are challenging and deficient in most college education ***,the continuous inspection paradigm has been widely used by developers on social coding sites(e.g.,GitHub)as an important method to ensure the internal quality of massive code *** paper presents a case where continuous inspection is introduced into the classroom setting to improve students’programming *** the study,we first designed a specific continuous inspection process for students’collaborative projects and built an execution environment for the *** then conducted a controlled experiment with 48 students from the same course during two school years to evaluate how the process affects their programming *** results show that continuous inspection can help students in identifying their bad coding habits,mastering a set of good coding rules and significantly reducing the density of code quality issues introduced in the ***,we describe the lessons learned during the study and propose ideas to replicate and improve the process and its execution platform.

关键词： continuous inspection programming quality SonarQube

A novel prognostic gene signature,nomogram and immune landscape based on tanshinone IIA drug targets for hepatocellular carcinoma:Comprehensive bioinformatics analysis and in vitro experiments

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BIOCELL 2023年第7期47卷 1519-1535页

作者： BOWEN PENG YUN GE gang yin School of Electronic Science and Engineering Nanjing UniversityNanjing210023China Department of Radiation Oncology Sichuan Cancer Hospital&InstituteChengdu610041China Radiation Oncology Key Laboratory of Sichuan Province Chengdu610041China

Tanshinone IIA,one of the main ingredients of Danshen,is used to treat hepatocellular carcinoma(HCC).However,potential targets of the molecule in the therapy of HCC are ***:In this study,we collected the tanshinone IIA targets from public databases for *** screened differentially expressed genes(DEGs)across HCC and normal tissues using mRNA expression profiles from The Cancer Genome Atlas(TCGA).Univariate Cox regression analysis and least absolute shrinkage and selection operator(LASSO)Cox regression models were used to identify and construct the prognostic gene ***:Finally,we discovered common genes across tanshinone IIA targets and HCC *** reported Fatty acid binding protein-6(FABP6),Polo-like Kinase 1(PLK1),deoxythymidylate kinase(DTYMK),Uridine Cytidine Kinase 2(UCK2),Enhancer of Zeste Homolog 2(EZH2),and Cytochrome P4502C9(CYP2C9)as components of a gene *** six-gene signature’s prognostic ability was evaluated using the Kaplan-Meier curve,time-dependent receiver operating characteristic(ROC),multivariate Cox regression analysis,and the *** mRNA level and protein expression of UCK2 were experimentally validated after treatment with different concentrations of tanshinone IIA in HEPG2 ***,TIMER2.0,and GEPIA2 tools were employed to explore the relationship between the prognostic signature and immune cell ***:We established a six-gene signature as a reliable model with significant therapeutic possibility for prognosis and overall survival estimation in HCC patients,which might also benefit medical decision-making for appropriate treatment.

关键词： Tanshinone IIA Hepatocellular carcinoma Immune cell infiltration Prognosis signatures

Vegetation dynamics and its response to climate change in Central Asia

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Arid Land 2016年第3期8卷 375-388页

作者： yin gang HU Zengyun CHEN Xi TIYIP Tashpolat State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China College of Resources and Environmental Sciences Xinjiang University Urumqi 830046 China University of Chinese Academy of Sciences Beijing 100049 China

The plant ecosystems are particularly sensitive to climate change in arid and semi-arid regions. However, the responses of vegetation dynamics to climate change in Central Asia are still unclear. In this study, we used the normalized difference vegetation index（NDVI） data to analyze the spatial-temporal changes of vegetation and the correlation of vegetation and climatic variables over the period of 1982–2012 in Central Asia by using the empirical orthogonal function and least square methods. The results showed that the annual NDVI in Central Asia experienced a weak increasing trend overall during the study period. Specifically, the annual NDVI showed a significant increasing trend between1982 and 1994, and exhibited a decreasing trend since 1994. The regions where the annual NDVI decreased were mainly distributed in western Central Asia, which may be caused by the decreased precipitation. The NDVI exhibited a larger increasing trend in spring than in the other three seasons. In mountainous areas, the NDVI had a significant increasing trend at the annual and seasonal scales; further, the largest increasing trend of NDVI mainly appeared in the middle mountain belt（1,700–2,650 m asl）. The annual NDVI was positively correlated with annual precipitation in Central Asia, and there was a weak negative correlation between annual NDVI and temperature. Moreover, a one-month time lag was found in the response of NDVI to temperature from June to September in Central Asia during 1982–2012.

关键词： NDVI precipitation temperature vegetation dynamics Central Asian countries

Study of Viscoelastic Properties of White Carbon Black Reinforced Synthetic Polyisoprene

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2016年第4期34卷 457-465页

作者： Guang-jun Cui Shi-wei Wang Peng-gang yin 郭林 Key Laboratory of Bio-Inspired-Smart Interfacial Science and Technology of Ministry of Education School of Chemistry and EnvironmentBeihang UniversityBeijing 100191China

The viscoelastic properties of synthetic polyisoprenes （PI） reinforced by white carbon black （WCB） have been investigated and compared with WCB reinforced natural rubber （NR）, including cure characteristics, physio-mechanical and dynamic mechanical properties. Compared with NR, PI loaded with the same amount of WCB （PI/WCB） exhibited shorter scorch time and optimal cure time, indicating that WCB fillers are comparatively easier to conjugate with PI. The tensile strength and elongation at break decreased with WCB filling in both PI and NR vulcanizates. The hardness of the rubber vulcanizates increased with the WCB filling in the rubber matrix. PI/WCB blends exhibited smaller hardness data, lower tensile strength, as well as lower elongation at break and tensile stress. Increasing the amount of WCB in rubber matrix induced the Payne effect. However, the Payne effect is much more obvious for the PI/WCB system, and PI/WCB also displayed higher storage modulus whereas lower loss modulus and loss tangent than NR/WCB, which could all be attributed to the poor dispersibilities of WCB in the PI matrix.

关键词： Reinforcement White carbon black Synthetic polyisoprene Natural rubber Viscoelastic properties Payne effect.

Determinants of pull-based development in the context of continuous integration

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2016年第8期59卷 53-66页

作者： Yue YU gang yin Tao WANG Cheng YANG Huaimin WANG College of Computer National University of Defense Technology National Laboratory for Parallel and Distributed Processing

The pull-based development model, widely used in distributed software teams on open source communities, can efficiently gather the wisdom from crowds. Instead of sharing access to a central repository,contributors create a fork, update it locally, and request to have their changes merged back, i.e., submit a pull-request. On the one hand, this model lowers the barrier to entry for potential contributors since anyone can submit pull-requests to any repository, but on the other hand it also increases the burden on integrators, who are responsible for assessing the proposed patches and integrating the suitable changes into the central repository. The role of integrators in pull-based development is crucial. They must not only ensure that pull-requests should meet the project’s quality standards before being accepted, but also finish the evaluations in a timely manner. To keep up with the volume of incoming pull-requests, continuous integration(CI) is widely adopted to automatically build and test every pull-request at the time of submission. CI provides extra evidences relating to the quality of pull-requests, which would help integrators to make final decision(i.e., accept or reject). In this paper, we present a quantitative study that tries to discover which factors affect the process of pull-based development model, including acceptance and latency in the context of CI. Using regression modeling on data extracted from a sample of Git Hub projects deploying the Travis-CI service, we find that the evaluation process is a complex issue, requiring many independent variables to explain adequately. In particular, CI is a dominant factor for the process, which not only has a great influence on the evaluation process per se, but also changes the effects of some traditional predictors.

关键词： pull-request continuous integration Git Hub distributed software development empirical analysis